My husband asked me to post this question for him. Not sure whether to post in Air Travel or the USA forum so will try both. He is flying into JFK in a few weeks and staying with friends. Looking for best way, easiest way to get from JFK to to 1 (One) Fifth Avenue? He will have a carryon bag only. Any help will be much appreciated.

Define what you mean by "best".

Easiest is a car service or taxi.

Least expensive is to use public transportation but that's time consuming.

Go here for a good summary of all the different options:
http://www.panynj.gov/airports/jfk.html

if he is not on a strict budget then taxi will be the easiest. If he is, then Air Train to LIRR to Penn station, then subway will be best.

Google maps will give directions by public transportation.

Very helpful information. Thanks so much!

Some ten years ago, several posters on this board recommended Carmel Limo for NYC airport transportation. I have been using them ever since, at least three times a year, and have always had a positive experience. The cost is not very different from a taxi.

http://www.carmellimo.com/index.html

The taxi is $52.80 plus tip & tolls for a total of ~$65-$70. Getting a taxi from the official dispatch line is certainly easiest.
Cheapest (and relatively easy) would be the AirTrain ($5 paid when you exit) to the E train ($2.75 or included if he's there long enough to use the 7 day unlimited metro card).

SkyTrain to Howard Beach then A Train direct to W4th/Washington Sq. Easier and more direct then using the E Train or LIRR.

Sorry, I mean AirTrain.

Another way is to take the Airtrain to the E train. Get off and take the Number 6 Lexington Local Downtown to Astor place. It is a very short walk from there.